title: Optic nerve head component responses of the multifocal electroretinogram in MS.
abstract: OBJECTIVE
  To employ a novel stimulation paradigm in order to elicit multifocal electroretinography (mfERG)-induced optic nerve head component (ONHC) responses, believed to be contingent upon the transformation in electrical transmission properties of retinal ganglion cell axons from membrane to saltatory conduction mechanisms, as they traverse the lamina cribrosa and obtain oligodendrocyte myelin. We further sought to characterize abnormalities in ONHC responses in eyes from patients with multiple sclerosis (MS).
  
  
  METHODS
  In 10 normal subjects and 7 patients with MS (including eyes with and without a history of acute optic neuritis), we utilized a novel mfERG stimulation paradigm that included interleaved global flashes in order to elicit the ONHC responses from 103 retinal patches of pattern-reversal stimulation.
  
  
  RESULTS
  The number of abnormal or absent ONHC responses was significantly increased in MS patient eyes compared to normal subject eyes (p < 0.001, by general estimating equation modeling, and accounting for age and within-subject, intereye correlations).
  
  
  CONCLUSIONS
  Studying the relationship between ONHC abnormalities and alterations in validated structural and functional measures of the visual system may facilitate the ability to dissect and characterize the pathobiological mechanisms that contribute to tissue damage in MS, and may have utility to detect and monitor neuroprotective or restorative effects of novel therapies.
authors.affiliation: Department of Neurology, University of Texas Southwestern Medical Center at Dallas, USA.
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Frohman
authors.forename: Shin Chien
authors.initials: SC
authors.lastname: Beh
authors.forename: Shiv
authors.initials: S
authors.lastname: Saidha
authors.forename: Zane
authors.initials: Z
authors.lastname: Schnurman
authors.forename: Darrel
authors.initials: D
authors.lastname: Conger
authors.forename: Amy
authors.initials: A
authors.lastname: Conger
authors.forename: John N
authors.initials: JN
authors.lastname: Ratchford
authors.forename: Carmen
authors.initials: C
authors.lastname: Lopez
authors.forename: Steven L
authors.initials: SL
authors.lastname: Galetta
authors.forename: Peter A
authors.initials: PA
authors.lastname: Calabresi
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
authors.forename: Ari J
authors.initials: AJ
authors.lastname: Green
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Frohman
mesh_terms: D000328:Adult; D004596:Electroretinography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000503:physiopathology*; D009898:Optic Disk / Q000502:physiology / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods*; D010865:Pilot Projects; D012165:Retinal Ganglion Cells / Q000502:physiology